before 900;1965-70for def 6; (noun) Middle Englishspede good luck, prosperity, rapidity, Old Englishspēd; cognate with Dutchspoed,Old High Germanspōt; akin to Old Englishspōwan to prosper, succeed; (v.) Middle Englishspeden to succeed, prosper, go with speed, Old Englishspēdan to succeed, prosper; cognate with Old Saxonspōdian,Old High Germanspuoten

1, 2. fleetness, alacrity, dispatch, expedition; hurry. Speed,velocity,quickness,rapidity,celerity,haste refer to swift or energetic movement or operation. Speed (originally prosperity or success) may apply to human or nonhuman activity and emphasizes the rate in time at which something travels or operates: the speed of light, of a lens, of an automobile, of thought.Velocity, a more learned or technical term, is sometimes interchangeable with speed : the velocity of light; it is commonly used to refer to high rates of speed, linear or circular: velocity of a projectile.Quickness, a native word, and rapidity, a synonym of Latin origin, suggest speed of movement or operation on a small or subordinate scale; quickness applies more to people (quickness of mind, of perception, of bodily movement ), rapidity more to things, often in a technical or mechanical context: the rapidity of moving parts; a lens of great rapidity.Celerity, a somewhat literary synonym of Latin origin, refers usually to human movement or operation and emphasizes expedition, dispatch, or economy in an activity: the celerity of his response.Haste refers to the energetic activity of human beings under stress; it often suggests lack of opportunity for care or thought: to marry in haste; a report prepared in haste.9. advance, favor. 11. accelerate. 16. See rush1 .

speed

/spiːd/

noun

1.

the act or quality of acting or moving fast; rapidity

2.

the rate at which something moves, is done, or acts

3.

(physics) a scalar measure of the rate of movement of a body expressed either as the distance travelled divided by the time taken (average speed) or the rate of change of position with respect to time at a particular point (instantaneous speed). It is measured in metres per second, miles per hour, etc

4.

a rate of rotation, usually expressed in revolutions per unit time

5.

a gear ratio in a motor vehicle, bicycle, etc

(in combination): a three-speed gear

6.

(photog) a numerical expression of the sensitivity to light of a particular type of film, paper, or plate See also ISO rating

7.

(photog) a measure of the ability of a lens to pass light from an object to the image position, determined by the aperture and also the transmitting power of the lens. It increases as the f-number is decreased and vice versa

Meaning "quickness of motion or progress" emerged in late Old English (usually adverbially, in dative plural, e.g. spedum feran), emerging fully in early Middle English. Meaning "gear of a machine" is attested from 1866. Meaning "methamphetamine, or a related drug," first attested 1967, from its effect on users. Speed bump is 1975; figurative sense is 1990s. Full speed is recorded from late 14c. Speed reading first attested 1965. Speedball "mix of cocaine and morphine or heroin" is recorded from 1909.

v.

Old English spedan "to succeed, prosper, advance" (see speed (n.)). Meaning "to go fast" is attested from c.1300. Meaning "to send forth with quickness" is first recorded 1560s; that of "to increase the work rate of" (usually with up) is from 1856. Related: Speeded; speeding.